KORTH AMERICAN LATER TERTIARY AND Ql^ATERNARY BRYOZOA. 129 



Fig. 25. — Genus Inversiula Jullien, 1888. 



A. /reversmta nufn;.r Jullien, 1888. Zooecium. (After JulUen, 1888.) 



B-F. Inversiula inversa Waters, 1889. B. Zooecia, X 25. C. Decalcified zooecia, X 50. Distinct 

 tubes occupy the place of the grooves. The interior membrane of the zooecial wall is not perforated by 

 the stellate pores. A stellate pore X 250 is represented at a. D. Three stages of growth, X 50. There 

 are deep grooves between the stellate pores. (B-D, after Waters, 1889.) E. Structure of the stellate 

 pores, X 200. (After Le\-insen, 1909.) F. Opercuhur, X 250. (After Waters, 1887.) 



Genus INVERSIULA JuIUen, 1888. 



1888. Inrersiula Jullien, Mission scientifique du Cap Horn. 1882-83, VI, Zoologie, Brj-ozoaires, 

 p. 41. 



No ovicell. The frontal is a tremocyst with stellate pores. The aperture is 

 elliptical and transverse. The convexity of the ascopore is turned toward the 

 aperture. Avicularia are present. No spines. 



Genotype. — Inversiula nutrix Jullien, 1888. 



Range. — Miocene-Kecent. 



The known species of this genus are: 



Inversiula nutrix Jullien, 1888. 



Inversiula { Microporella) inversa Waters, 1889. 



Inversiula (Microporella) airensis Maplestone, 1910. 



Inversiula (Microporella) quadricornis Maplestone, 1910. 



Group 3. HIPPOPORAE Canu and Bassler, 1917. 

 Genus HIPPOPORINA Neviani, 1895. 



(For description see Bulletin 106, U. S. National Museum, p. 374.) 



HIPPOPORINA PUSILLA. new species. 



Plate 45, figs. 8, 9. 



Description. — The zoarium incrusts sponges and corals. The zooecia are dis- 

 tinct, separated by a furrow, small, elongate, elliptical; the frontal is an absolutely 

 smooth olocyst. The apertura is very small, sinrounded by a thick peristome which 



